John McEnroe told ESPN.com on Wednesday that his statement about taking steroids in recent publications was misunderstood, clarifying that the drugs he received were given as painkillers. The drugs McEnroe said he took are not considered medically to be the same as anabolic steroids, which are the drugs thought of as performance enhancing.

The former No. 1 ranked tennis player in the world, who won 77 singles titles and seven Grand Slam titles in his career, told a British newspaper on Sunday that he was unaware that he was being given a form of steroid. But he told ESPN.com on Wednesday that the differentiation between painkillers and performance enhancers wasn't made by the reporter.

McEnroe, who announced on Wednesday that he will be hosting a prime-time one-hour show that debuts next spring on CNBC, said he was given two drugs -- Butazolidin and prednisone -- for six years. Butazolidin is a nonsteriodal inflammatory drug, while prednisone is a corticosteroid.

"Years later, after I had stomach ulcer issues, I found out that Butazolidin was no longer being prescribed to horses because it was too strong," he said.

McEnroe, who retired in 1991, spent the majority of his career untested for performance-enhancing drugs as the tennis anti-doping program did not begin those types of tests until the ATP Tour was formed in 1990. Prior to then, the focus was only on recreational drugs.

After being told of the original news article about McEnroe, Andre Agassi -- who said for 13 events last year he underwent 11 urine tests and eight blood tests, three of which were outside of competition -- said he was surprised over the admission.

"I just find myself [at] a bit of a loss for words when it comes to that sort of stuff being expressed," Agassi reportedly said.

Last week, Greg Rusedski said that he tested positive for the banned steroid Nandrolone in July but claimed that many tennis players have shown high levels in their body.

McEnroe's admission, which he said he had discussed before, was meant to highlight the fact that players have to be careful about what goes into their bodies.

Said McEnroe: "I think, in tennis, illegal drugs are much less of a problem than in other sports."

Darren Rovell, who covers sports business for ESPN.com, can be reached at darren.rovell@espn3.com.